Spoon rice mixture on top of pounded chicken breasts; fold over and secure sides with wooden toothpicks soaked in water. Wipe off outsides of chicken breasts with paper towel.

Coat a large skillet with cooking spray and place over medium-high heat until hot. Cook stuffed chicken breasts 1 minute on each side or just until golden brown. Transfer chicken to shallow baking pan. Bake in preheated oven for 8 to 10 minutes.